The installation of scaffolds or workbenches at a construction site may require extensive, specialized structural components that must be taken to a job site, assembled for use and then disassembled and removed after use. Moreover, there is often a need for a standard brace for supporting work benches or shelves that can securely mount to the upright studs of a frame. What is needed a system that includes portable, standardized, reusable braces and fittings that can mount to commonly available construction materials such as upright 2×4 studs to provide the supporting structure for a scaffold, a shelf or a workbench. What is also needed is such a structural system that can be assembled and disassembled very rapidly.